A K-band CMOS Differential Vackar VCO With the Gate Inductive Feedback

作者：Tai Nghia Nguyen^*; Lee Jong Wook

来源：IEEE Transactions on Circuits and Systems II-Express Briefs, 2012, 59(5): 257-261.

DOI：10.1109/TCSII.2012.2188472

• Inductive feedback
• low phase noise
• transformer
• Vackar
• voltage-controlled oscillators (VCOs)

This brief presents a K-band differential Vackar voltage-controlled oscillator (VCO) with gate inductive feedback which enhances negative impedance and thus simplifies the startup condition. Simple analysis and simulations examine the transistor loading effect and amplitude stability. Results indicate that the Vackar VCO has improved amplitude stability compared to the Colpitts VCO. The improved amplitude stability is favorable for suppressing amplitude-to-phase noise conversion. The Vackar VCO was implemented in a 0.13-mu m RF CMOS process. The oscillation frequency ranged from 19 to 19.95 GHz. The measured phase noise at 1-MHz offset was - 103 dBc/Hz at 19.5 GHz with a figure of merit of - 182 dB.

• 出版日期2012-5